1. Technical Field
The present invention relates to indexing methods and systems and, in particular, to methods and systems for indexing signal options employed in communication links.
2. Description of the Related Art
In many communication systems, control signals are employed between transmitters and receivers to enable the identification and proper setup of a communication link. These signals include, but are not limited to, reference signals and signals conveying information of other signal options such as modulation format, coding rate, precoding index, assigned subbands and so on. For example, certain communication systems dynamically allocate a number of subbands from a set of available subbands to the users it services for purposes of transmitting data to the users on the allocated subbands. It is often desirable to reduce the signaling, as it increases overhead of the communication systems. Different indexing approaches for conveying control information have been described in the literature. For example, with regard to subband indexing, a conventional approach employs a known algorithm that is based on the enumerative source coding problem to compute indices for a set of binary permutations.